D. Inclined Plane Inclined Plane

sloping surface used to raise objects

hl

h

lIMA

E. ScrewScrew

inclined plane wrapped in a spiral around a cylinder

F. WedgeWedge

a moving inclined plane with 1 or 2 sloping sides

F. WedgeZipper

2 lower wedges push teeth together1 upper wedge pushes teeth apart

Problems How much force must be exerted to

push a 450 N box up a ramp that is 3 m long and 1.2 m high?

GIVEN:

Fe = ?

Fr = 450 N

l = 3 m

h = 1.2 m

WORK:IMA = l ÷ hIMA = (3 m)÷(1.2 m)IMA = 2.5

IMA

l

hMA

Fr

Fe

Fe = Fr ÷ MAFe = (450 N)÷(2.5)Fe = 180 N